Is it safe to drink the tap water?

No. Stick to bottled water, which is available at every convenience store.

Should I wear shorts or long pants?

Wear light, breathable long pants or long skirts. They protect you from the sun and are required for entry into most temples.

When is the absolute hottest time of the year?

April is historically the hottest month in Bangkok, with humidity levels often making it feel like 40°C+ (104°F+).

Staying Cool in Bangkok's Heat and Humidity

Beat the Bangkok heat by limiting outdoor activity to before 10:00 AM or after 5:00 PM and using the city's extensive air-conditioned mall network as your primary transit route. Carry a personal fan and prioritize public transport like the BTS Skytrain over walking on street level to avoid the worst of the asphalt heat.

Use the Skywalks. In areas like Siam, Chit Lom, and Phloen Chit, use the elevated walkways. They connect major malls and stations, keeping you off the pavement and usually near building cooling vents.
Strategic Transit. Take the BTS Skytrain or MRT subway. They are heavily air-conditioned and are significantly faster than sitting in a taxi stuck in traffic, where the engine heat contributes to your discomfort.
The Mall Strategy. If you are walking long distances, 'mall-hop.' Bangkok malls are designed for foot traffic. Walk through CentralWorld or Siam Paragon to cut across city blocks in climate-controlled environments.
Hydration Management. Buy 600ml water bottles at 7-Eleven for 10 THB. Do not wait until you are thirsty; drink at least one full bottle every two hours to replace fluids lost through sweat.
The Cold Towel Trick. Buy a 'Cooling Towel' or keep a wet handkerchief in a ziplock bag. Placing it on the back of your neck or your pulse points brings your core temperature down quickly.

Is it safe to drink the tap water?: No. Stick to bottled water, which is available at every convenience store.
Should I wear shorts or long pants?: Wear light, breathable long pants or long skirts. They protect you from the sun and are required for entry into most temples.
When is the absolute hottest time of the year?: April is historically the hottest month in Bangkok, with humidity levels often making it feel like 40°C+ (104°F+).